uluaz
09-28-2006, 04:07 AM
I have a noise that I think :? is coming from my tail gear box on my Xcell gasser 1005. Key word "I think." It has the plastic gearbox. I've already gone thru the main frame area of the heli. Checked every single bearing from the main shaft bearing to the clutch bearings to the tail drive bearings. I did replace a notchy lower main shaft bearing. Re-adjusted the main gear mesh and tail drive mesh to the crown gear as well as the pinion gear mesh . After all that still got the noise so I tore down the tail gearbox.Bearings look fine. Gears look ok visually, but, there is some backlash between the gears. Is it desireable to have "zero" backlash as long as it doesn't bind up. Or is a little backlash ok. I would guess I have about 6 gallons on fuel thru the airframe. I bought it used (like new) so I have never messed with the tail gears. If I do spin the main gear and listen to the tail gears I can hear some gear noise. I am wanting to order me a new set of tail gears. What kind of backlash should I set it for? Is there a general "rule of thumb" to check the backlash if it's out of specs. Maybe like holding the crown gear and moving the tail blades?? Heli still flies good though. Just has that noise.